The present invention relates, in general, to surgical instruments and, more particularly, to an articulation and actuation mechanism for surgical instruments.
This application is related to the following copending patent applications: application Ser. No. 08/770,550 filed Dec. 23, 1996; application Ser. No. 08/808,652 filed Feb. 28, 1997; application Ser. No. 091255,519 filed Feb. 22, 1999; and application Ser. No. 09/464,973 filed Dec. 16, 1999 which are hereby incorporated herein by reference.
Ultrasonic instruments, including both hollow core and solid core instruments, are used for the safe and effective treatment of many medical conditions. Ultrasonic instruments, and particularly solid core ultrasonic instruments, are advantageous because they may be used to cut and/or coagulate organic tissue using energy in the form of mechanical vibrations transmitted to a surgical end-effector at ultrasonic frequencies. Ultrasonic vibrations, when transmitted to organic tissue at suitable energy levels and using a suitable end-effector, may be used to cut, dissect, or cauterize tissue. Ultrasonic instruments utilizing solid core technology are particularly advantageous because of the amount of ultrasonic energy that may be transmitted from the ultrasonic transducer, through the waveguide, to the surgical end-effector. Such instruments are particularly suited for use in minimally invasive procedures, such as endoscopic or laparoscopic procedures, wherein the end-effector is passed through a trocar to reach the surgical site.
Solid core ultrasonic instruments adapted for use in surgery and, more particularly, for use in minimally invasive surgery, are well known in the art. For example, U.S. Pat. No. 5,322,055 illustrates an ultrasonic surgical shears that utilizes solid core ultrasonic technology, while U.S. Pat. No. 5,324,299 illustrates an ultrasonic hook blade end-effector for use in surgical applications. In addition, articulating instruments for use in minimally invasive surgery are also known in the art. For example, U.S. Pat. No. 5,409,498 describes an articulating endocutter for use in cutting and stapling tissue.
Many ultrasonic surgical instruments used for cutting and coagulation rely upon relatively stiff, solid core ultrasonic waveguides to efficiently deliver energy from the transducer to the end-effector. In such instruments it may be desirable to articulate the end-effector in order to provide the surgeon with flexibility in engaging hard to reach structures. However, the relatively stiff solid core ultrasonic waveguides and the limited structural space available in minimally invasive instruments make it difficult to design appropriate mechanisms for articulating end-effectors in such devices. One option, which is illustrated and described in U.S. patent application Ser. No. 08/770,550 previously incorporated herein by reference, involves separating the waveguide into two or more segments which may be moved independently to provide articulation.
Flexible high power ultrasonic surgical instruments are also available. Flexible ultrasonic surgical instruments such as atherosclerosis treatment devices, thrombolysis devices, or some stone crushing devices are typically thin wires encased in a polymeric sheath, are relatively flexible, and articulate if assisted with known flexible endoscopy articulation means. For example, U.S. Pat. No. 5,380,274 describes a flexible ultrasonic catheter, and U.S. Pat. No. 4,108,211 describes a flexible endoscope mechanism.
It would, therefore, be advantageous to design an improved mechanism for articulating and actuating surgical instruments. It would further be advantageous to design an improved mechanism for articulating and actuating surgical instruments wherein the end-effector is both rotatable and articulatable. It would further be advantageous to design an articulating solid core ultrasonic surgical instrument which could be passed through a trocar or other surgical access device and the end-effector could be articulated utilizing a handle positioned outside of the surgical access device. The present invention incorporates improvements to known ultrasonic surgical instruments to provide these advantages.
An improved actuation mechanism for a surgical instrument is described. The mechanism includes an actuating arm and a collar operatively connected to the actuating arm. The collar converts rotation of the actuating arm into a plurality of actuations of the surgical instrument. In one embodiment the collar includes two ranges of motion, where the first range is used to articulate the surgical instrument, and the second range is used to actuate the surgical instrument.